The present invention generally relates to a cutting mechanism for severing a continuous piece of elongated material. More specifically, the present invention is a cutting mechanism including a floating insert blade that interacts with a reciprocal cutting blade to ensure the proper orientation between the blades such that the cutting mechanism is particularly useful in severing fiber optic cables.
Currently available cutting mechanisms used to sever lengths of electrical wiring typically include either bypass blades or collinear blades. Although both of these types of cutting blades are useful in severing electrical wiring that includes a metallic conductor surrounded by a layer of insulation, problems exist when utilizing either of the cutting mechanisms to cut a length of fiber optic cable. Specifically, both bypass cutting blades and collinear cutting blades have problems cutting fiber optic cable that includes a layer of Kevlar strands to protect the internal fiber optic strand.
Typical bypass blades include a pair of cutting blades that each include a cuffing edge. The bypass blades are operated such that the cutting edge of each blade approaches and passes the opposed cutting edge to sever the material positioned therebetween in a guillotine-type fashion. When bypass blades are used to cut fiber optic cables, any gap between the cutting edge on the opposed blades can allow the Kevlar strands to pass between the blades and remain uncut after the process has been completed.
A cutting mechanism including collinear blades includes two blades contained in a common plane that abut each other to sever the material between the two cutting edges. During repeated use of the collinear blades, the cutting edge of each blade becomes worm, such that the cooperating blades will have trouble cutting the small, individual Kevlar strands contained in the fiber optic cable.
In general, the problem in cutting the fiber optic cable including the layer of Kevlar fibers resides in the tight tolerances that must be maintained between the cutting edges of the cutting blades. If the cutting edges of the cutting blades are not maintained in nearly perfect alignment, the Kevlar fibers remain uncut and create an undesirable result.
Therefore, it is an object of the present invention to provide a cutting mechanism that can be used to cleanly cut a fiber optic cable including a layer of Kevlar strands. Additionally, it is an object of the present invention to provide a cutting mechanism that includes wear-resistant cutting blades to reduce wear during repeated use of the cutting mechanism with a fiber optic cable. Further, it is an object of the present invention to provide cutting blades that can be readily replaced or rotated.
The present invention is directed to a cutting mechanism used to sever an elongated material. In particular, the cutting mechanism of the invention is particularly useful in cutting a fiber optic cable including a layer of Kevlar strands.
The cutting mechanism includes a cutting blade and an insert blade that each include a cutting edge. The movement of the cutting blade past the insert blade severs the elongated material in the desired manner. The insert blade is mounted within a blade receptacle formed in a stationary mounting block. The blade receptacle is defined by an inner surface recessed from an attachment surface of the blade housing by a sidewall. A bias member is positioned between the insert blade and the inner surface of the blade receptacle to urge a generally planar outer surface of the insert blade outward past the attachment surface of the blade housing.
A guide block is securely attached to the blade housing. Specifically, a pair of attachment strips formed on the guide block contact the attachment surface of the blade housing when the guide block is attached to the blade housing. A blade contact surface is formed on the guide block and is recessed from the attachment strips, such that when the guide block is attached to the blade housing, the recessed blade contact surface forms a blade guideway between the joined blade housing and guide block.
The blade guideway receives the cutting blade such that the cutting blade can reciprocate between a retracted position and an extended position relative to the stationary blade housing. The cutting blade includes a pair of spaced guide legs that extend from the cutting edge formed on the cutting blade. The guide legs are spaced by an open channel that is larger than the maximum diameter of elongated material to be cut by the cutting mechanism.
When an elongated material, such as a fiber optic cable, is inserted into the cutting mechanism, the elongated material passes completely through the cutting mechanism. Specifically, the material to be cut passes through a material-receiving opening contained in the blade housing, the open channel formed in the cutting blade, and an open slot formed in the guide block.
As the cutting blade moves from its retracted position to its extended position, the outer face surface of the insert blade initially comes into contact with a cutting face surface formed on each guide leg of the cutting blade. The interaction between the outer face surface of the insert blade and the cutting face surface on each guide leg causes the cutting edge on the insert blade and the cutting edge on the cutting blade to be properly aligned. The bias member positioned behind the insert blade ensures that the insert blade is held in the proper alignment relative to the cutting blade as the cutting blade moves to the extended position.
As a further feature of the invention, the insert blade includes multiple cutting edges such that the insert blade can be indexed upon each cutting edge becoming worn. Specifically, the insert blade includes four separate cutting edges such that the single insert blade can be used until each of the four cutting edges becomes worn. Preferably, both the insert blade and the cutting blade are formed from carbide to further reduce wear during repeated use of the cutting mechanism.
The combination of the guide block and the blade housing form the blade guideway that receives the cutting blade. The blade guideway supports the cutting blade in all directions to prevent the cutting blade from twisting while the cutting blade severs the fiber optic cable. However, even if slight twisting occurs, the bias force exerted by the bias element on the insert blade retains the desired orientation between the insert blade and the cutting blade to ensure a clean cut of the Kevlar fibers contained within the fiber optic cable.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.